Just to refresh your memory, parallel lines are lines that are the same distance apart, and perpendicular lines are lines that intersect at a right angle - which is the same as a 90 degree angle.

So we know what these lines look like on a graph, but how can we recognize equations of lines that are parallel or perpendicular? There is an easy answer for this question of parallel lines. The equations of parallel lines have slopes that are the same i.e. when written in slope-intercept form, the m-values of the lines will be the same.

How can we recognize equations of lines that are perpendicular? The answer to this question is not quite as easy as for parallel lines, so pay attention! The product of the slopes of perpendicular lines is equal to -1, meaning when the lines are written in slope-intercept form, the product of the m-values will be equal to -1.

So, just by looking at the equations, without plotting points on a graph and drawing a line, you can determine if the slopes are parallel or perpendicular? You sure can! To learn more about the slopes of parallel and perpendicular lines and see some awesome examples, tune in to this video.